CasperSecurity
# -*- test-case-name: twisted.protocols.haproxy.test.test_v1parser -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
IProxyParser implementation for version one of the PROXY protocol.
"""
from typing import Tuple, Union
from zope.interface import implementer
from twisted.internet import address
from . import _info, _interfaces
from ._exceptions import (
InvalidNetworkProtocol,
InvalidProxyHeader,
MissingAddressData,
convertError,
)
@implementer(_interfaces.IProxyParser)
class V1Parser:
"""
PROXY protocol version one header parser.
Version one of the PROXY protocol is a human readable format represented
by a single, newline delimited binary string that contains all of the
relevant source and destination data.
"""
PROXYSTR = b"PROXY"
UNKNOWN_PROTO = b"UNKNOWN"
TCP4_PROTO = b"TCP4"
TCP6_PROTO = b"TCP6"
ALLOWED_NET_PROTOS = (
TCP4_PROTO,
TCP6_PROTO,
UNKNOWN_PROTO,
)
NEWLINE = b"\r\n"
def __init__(self) -> None:
self.buffer = b""
def feed(
self, data: bytes
) -> Union[Tuple[_info.ProxyInfo, bytes], Tuple[None, None]]:
"""
Consume a chunk of data and attempt to parse it.
@param data: A bytestring.
@type data: L{bytes}
@return: A two-tuple containing, in order, a
L{_interfaces.IProxyInfo} and any bytes fed to the
parser that followed the end of the header. Both of these values
are None until a complete header is parsed.
@raises InvalidProxyHeader: If the bytes fed to the parser create an
invalid PROXY header.
"""
self.buffer += data
if len(self.buffer) > 107 and self.NEWLINE not in self.buffer:
raise InvalidProxyHeader()
lines = (self.buffer).split(self.NEWLINE, 1)
if not len(lines) > 1:
return (None, None)
self.buffer = b""
remaining = lines.pop()
header = lines.pop()
info = self.parse(header)
return (info, remaining)
@classmethod
def parse(cls, line: bytes) -> _info.ProxyInfo:
"""
Parse a bytestring as a full PROXY protocol header line.
@param line: A bytestring that represents a valid HAProxy PROXY
protocol header line.
@type line: bytes
@return: A L{_interfaces.IProxyInfo} containing the parsed data.
@raises InvalidProxyHeader: If the bytestring does not represent a
valid PROXY header.
@raises InvalidNetworkProtocol: When no protocol can be parsed or is
not one of the allowed values.
@raises MissingAddressData: When the protocol is TCP* but the header
does not contain a complete set of addresses and ports.
"""
originalLine = line
proxyStr = None
networkProtocol = None
sourceAddr = None
sourcePort = None
destAddr = None
destPort = None
with convertError(ValueError, InvalidProxyHeader):
proxyStr, line = line.split(b" ", 1)
if proxyStr != cls.PROXYSTR:
raise InvalidProxyHeader()
with convertError(ValueError, InvalidNetworkProtocol):
networkProtocol, line = line.split(b" ", 1)
if networkProtocol not in cls.ALLOWED_NET_PROTOS:
raise InvalidNetworkProtocol()
if networkProtocol == cls.UNKNOWN_PROTO:
return _info.ProxyInfo(originalLine, None, None)
with convertError(ValueError, MissingAddressData):
sourceAddr, line = line.split(b" ", 1)
with convertError(ValueError, MissingAddressData):
destAddr, line = line.split(b" ", 1)
with convertError(ValueError, MissingAddressData):
sourcePort, line = line.split(b" ", 1)
with convertError(ValueError, MissingAddressData):
destPort = line.split(b" ")[0]
if networkProtocol == cls.TCP4_PROTO:
return _info.ProxyInfo(
originalLine,
address.IPv4Address("TCP", sourceAddr.decode(), int(sourcePort)),
address.IPv4Address("TCP", destAddr.decode(), int(destPort)),
)
return _info.ProxyInfo(
originalLine,
address.IPv6Address("TCP", sourceAddr.decode(), int(sourcePort)),
address.IPv6Address("TCP", destAddr.decode(), int(destPort)),
)